• Korean Journal of Veterinary Service
• /
• v.34 no.4
• /
• pp.341-352
• /
• 2011

Colibacillosis in pigs remain a major swine industry bruden worldwide. Although some progress has been made in treating collibacillosis in pigs by using biosecurity and antimicrobials, it still remain a considerable problem. The use of host-specific bateriophages as a biocontrol is one possible alternative. The purpose of this study was to evaluate the effect of bacteriophage against enterotoxigenic Escherichia coli (ETEC) K88 infection in piglets. Twenty-eight piglets were randomly divided into four groups and each group was allocated with 7 pigs. Group B, C and D were inoculated with 5 ml of ETEC K88 ($1{\times}10^8$ CFU/ml) per head of piglet via oral. Group C and D were fed with bacteriophages (Group C, $1.0{\times}10^6$ PFU/g; Group D, $1.0{\times}10^8$ PFU/g; CJ CheilJedang Corp., Korea) orally as treatment. In piglets administrated bacteriophages and challenged with ETEC K88 (Group C and D), Clinical signs and the growth performance were improved and antibody titers were maintained low level compared with piglets challenged with ETEC K88 (Group B, P<0.05). Group B were shown high pH in the alimentary tracts compared with other piglets (P<0.05). In quantitative analysis by real-time PCR, the results of Group C and D were lower than those Group B in faecal and intestinal samples (P<0.05). Severe villus atrophy and crypt hyperplasia were observed in Group B consequently V/C ratio increased, compared with other piglets. These results indicate that feeding with bacteriophage has effect to prevent ETEC K88 infection in piglets and suggest that use of bacteriophage can be considered a valid antibiotic alternative.

• The Journal of the Korean Society for Microbiology
• /
• v.35 no.5_6
• /
• pp.367-367
• /
• 2000

• Bulletin of Food Technology
• /
• v.23 no.4
• /
• pp.544-551
• /
• 2010

식품산업에서 박테리오파아지를 첫째, 동물 보건에서 항생제 대체품으로서, 둘째, 식품에서 바이오보존제(biopreservative)로서, 셋째, 식품 체인에서 병원성 세균을 검출하기위한 도구로서 다양하게 이용하고자 최근에 널리 인지하고 있다. 박테리오파아지는 바이러스로서 세균을 감염시키고 용해하는 특성이 있으며, 식품 안전과 관련하여, 1) 포유 동물세포에 무해하여 박테리오파아지를 안전하게 이용할 가능성, 2) 발효식품에 적절한 스타터 역할을 하거나 천연 미생물균총을 그대로 보존하는 박테리오파아지의 높은 숙주 선택성이라는 2가지 특징을 지니고 있다. 최근에는 식품첨가물로서 박테리오파아지를 '먹을 수 있는 바이러스'로 인정할 수 있을지 논의되고 있다. 식품유래 병원성 세균을 제어하기 위한 파아지의 이용가능성과 생물학 분야에서 관련되는 기초연구를 하고자 할 때 생기는 제한점 등에 대해서 고찰하고자 한다.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.6
• /
• pp.740-747
• /
• 2014

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a very serious disease in rice-growing regions of the world. In spite of their economic importance, there are no effective ways of protecting rice plants from this disease. Bacteriophages infecting Xoo affect the population dynamics of the pathogen and consequently the occurrence of the disease. In this study, we investigated the diversity, host range, and infectivity of Xoo phages, and their use as a bicontrol agent on BLB was tested. Among the 34 phages that were isolated from floodwater in paddy fields, 29 belonged to the Myoviridae family, which suggests that the dominant phage in the ecosystem was Myoviridae. The isolated phages were classified into two groups based on plaque size produced on the lawn of Xoo. In general, there was a negative relationship between plaque size and host range, and interestingly the phages having a narrow host range had low efficiency of infectivity. The deduced protein sequence analysis of htf genes indicated that the gene was not a determinant of host specificity. Although the difference in host range and infectivity depending on morphotype needs to be addressed, the results revealed deeper understanding of the interaction between the phages and Xoo strains in floodwater and damp soil environments. The phage mixtures reduced the occurrence of BLB when they were treated with skim milk. The results indicate that the Xoo phages could be used as an alternative control method to increase the control efficacy and reduce the use of agrochemicals.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.4
• /
• pp.457-463
• /
• 1999

The physical map of bacteriophage $\PhiFC1$ DNA was constructed with the restriction endonucleases SalI, BamHI, EcoRI, XbaI, and AvaI. The 40.5-kb DNA restriction map is shown to be circularly permuted representing the headful packaging mechanism of the phage. The DNA restriction fragments containing the packaging initiation site(pac) was localized on the restriction map and the nucleotide sequences of the region were analyzed. Four open reading frames (ORFs), following one another with the same orientation, were found at the region. The 2nd ORF (ORF-ts) has significant amino acid sequence homologies to the previously known terminase small subunits of other bacteriophages. The putative terminase small subunit gene has a presumptive NTP-hydrolysis motif and a helix-turn-helix motif. The cleavage site for the first round of packaging was found to be located at the coding sequence of the putative terminase small subunit gene. The fourth ORF, even if partially sequenced, has a good amino acid sequence homology to the portal vertex proteins of other bacteriophages representing the evolutionarily conserved arrangements of genes near the pac site of this bacteriophage, $\PhiFC1$.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.2
• /
• pp.234-241
• /
• 2017

Potato peels (PP) contain several bioactive compounds. These compounds are known to provide human health benefits, including antioxidant and antimicrobial properties. In addition, these compounds could have effects on human enteric viruses that have not yet been reported. The objective of the present study was to evaluate the phenolic composition, antioxidant properties in the acidified ethanol extract (AEE) and water extract of PP, and the antiviral effects on the inhibition of Av-05 and MS2 bacteriophages, which were used as human enteric viral surrogates. The AEE showed the highest phenolic content and antioxidant activity. Chlorogenic and caffeic acids were the major phenolic acids. In vitro analysis indicated that PP had a strong antioxidant activity. A 3 h incubation with AEE at a concentration of 5 mg/ml was needed to reduce the PFU/ml (plaque-forming unit per unit volume) of Av-05 and MS2 by 2.8 and $3.9log_{10}$, respectively, in a dose-dependent manner. Our data suggest that PP has potential to be a source of natural antioxidants against enteric viruses.

• Genes and Genomics
• /
• v.40 no.12
• /
• pp.1383-1388
• /
• 2018

The development of therapeutic bacteriophages will provide several benefits based on an understanding the basic physiological dynamics of phage and bacteria interactions for therapeutic use in light of the results of antibiotic abuse. However, studies on bacteriophage therapeutics against microbes are very limited, because of lack of phage stability and an incomplete understanding of the physiological intracellular mechanisms of phage. The major objective of this investigation was to provide opportunity for development of a novel therapeutic treatment to control respiratory diseases in swine. The cytokine array system was used to identify the secreted cytokines/chemokines after Bordetella bronchiseptica infection into swine nasal turbinate cells (PT-K75). We also performed the real-time quantitative PCR method to investigate the gene expression regulated by B. bronchiseptica infection or bacteriophage treatment. We found that B. bronchiseptica infection of PT-K75 induces secretion of many cytokines/chemokines to regulate airway inflammation. Of them, secretion and expression of IL-$1{\beta}$ and IL-6 are increased in a dose-dependent manner. Interestingly, membrane-bound mucin production via expression of the Muc1 gene is increased in B. bronchiseptica-infected PT-K75 cells. However, cytokine production and Muc1 gene expression are dramatically inhibited by treatment with a specific B. bronchiseptica bacteriophage (Bor-BRP-1). The regulation of cytokine profiles in B. bronchiseptica-induced inflammation by B. bronchiseptica bacteriophage is essential for avoiding inappropriate inflammatory responses. The ability of bacteriophages to downregulate the immune response by inhibiting bacterial infection emphasizes the possibility of bacteriophage-based therapies as a novel anti-inflammatory therapeutic strategy in swine respiratory tracts.

• Journal of Applied Biological Chemistry
• /
• v.62 no.3
• /
• pp.287-292
• /
• 2019

Pseudomonas tolaasii causes brown blotch disease on the oyster mushroom (Pleurotus ostreatus). Various pathogenic strains of P. tolaasii were isolated and divided into three subtypes, $P1{\alpha}$, $P1{\beta}$, and $P1{\gamma}$. For phage therapy, bacteriophages against to these subtype strains were applied to mushroom cultivation and very successful to prevent from the disease. In this study, bacteriophages were isolated against the representative strains of subtype pathogens and their polyclonal antibodies were synthesized to investigate structural relationship among capsid proteins of phages. Phage preparations over $10^{10}pfu/mL$ were injected to rabbit thigh muscle and polyclonal antibodies were obtained after three times of boost injection. Titers of the antibodies obtained were over $2{\times}10^7Ab/mL$ for the phage ${\phi}6264$, $1{\times}10^6Ab/mL$ for the phage ${\phi}HK2$, and $1{\times}10^7Ab/mL$ for the phage ${\phi}HK19$ and phage ${\phi}HK23$. High specific activities were observed between antibodies and the corresponding bacteriophages. Some cross-reactivities between the antibodies and non-corresponding bacteriophages were also measured. Antibody $Ab{\phi}6264$ inactivated all phages of $P1{\alpha}$ subtype and only phage ${\phi}HK16$ among $P1{\beta}$ subtype phages. Antibody $Ab{\phi}HK23$ of $P1{\gamma}$ subtype neutralized all phages of $P1{\beta}$ subtype as well as the phage ${\phi}HK23$, showing the widest phage-inactivation range. When the structural-similarity studies of phages were investigated by using phage antibodies, closeness obtained by phylogenetic analysis of 16S rRNA genes of pathogenic strains were quite different from that of polyclonal antibody-specific structural similarity of phage capsid proteins. In conclusion, there is weak correlation between the host strain specificity of bacteriophage and its capsid structural similarity measured by phage antibodies.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.135.1-135
• /
• 2003

A technique for detection of Xanthomonas axonopodis pv. citri, a causal bacterium of canker on Unshiu orange fruits, was developed using bacteriophage. Procedure for the detection was designed on the basis of the previous reports that one group(CPI) of X. axonopodis pv. citri bacteriophage and corresponding two Iysotypes distributed in Korea. First, fruit surface was washed with sterile distilled water and pellet was obtained from centrifugation. The pellet was resuspended in Wakimoto's potato semi-synthetic broth medium and divided equally into two parts. One part was heated in boiling water to kill bacterial cells. Bacteriophages(CP$_1$) were respectively added into two parts and 0.1 ml from each part was mixed with soft agar medium. After incubation for 18 hrs at 25$^{\circ}C$, the causal bacterium of canker was determined based on plaques formed on the medium. This procedure can be effectively used for detection of living bacterial pathogen on fruit surfaces of Unshiu orange.

• Food Science and Biotechnology
• /
• v.16 no.3
• /
• pp.398-403
• /
• 2007

The effectiveness of phage biocontrol depends on the activity of bacteriophage in a given environment. In order to investigate the infectivity and the stability of bacteriophages in representative environments, three virulent phages, Listeria phage A511, Salmonella phage Felix O1, and Escherichia coli phage T7, were subjected to different temperatures, pHs and salt concentrations (NaCl). Phage infectivity was also determined in the presence of divalent cations ($Mg^{2+}$ or $Ca^{2+}$). As a result, three phages exhibited a wide range of survival rates under various environments. Phage infectivity was directly correlated with bacterial growth under the applied conditions. One exception was Felix O1 that did not kill Salmonella grown in low pH (4.5). The failure was attributed to defective adsorption of Felix O1. This finding is significant as it provides an explanation for the inefficient phage biocontrol. Therefore, such information is crucial to improve phage biocontrol of pathogens.